A naturally occurring substance in lemon, orange, caraway and dill. Constitutes about 98% of orange peel oil by weight. Used as an insecticide and insect repellent. Widely used for control of fleas, lice, mites and ticks. Virtually non-toxic to warm-blooded animals, but can cause skin sensitivity and irritation. Pleasant lemon-like odor. Practically insoluble in water but miscible with ethanol. Example of commercial source: “ Natures Answer Flea and Tick Dip” contains 78.2% d-limonene and the label recommends diluting the product at a ratio of 3 parts product to 256 parts water (= 0.9%) and then applying directly to the pet. Major effects, including neural and behavioral toxicity, rapidly occur in Lumbriculus at 0.009%, or less. This is ≤ 1/100th of the recommended concentration for pets and serial dilutions can be made from this concentration. (see Karr et al., 1990
plant-derived Limonene occurs naturally in many essential oils we use: bay, bergamot, black pepper, chamomile, cistus, citronella, clary sage, coriander, cypress, elemi, eucalyptus, frankincense, galbanum, geranium, ginger, grapefruit, helichrysum, ho leaf, juniper, lavandin, lavender, lemongrass, lime, litsea, mandarin, neroli, niaouli, orange, palmarosa, peppermint, petitgrain, pine, Roman chamomile, rosemary, Spanish sage, spearmint (garden mint), tagetes and tea tree. It smells like oranges and is used as a natural flavour in our toothpastes. Some people are sensitive to this constituent.
Limonene is a hydrocarbon, classed as a terpene. It is a colourless liquid at room temperatures with an extremely strong smell of oranges. It takes its name from the lemon, as the rind of the lemon, like other citrus fruits, contains considerable amounts of this chemical compound, which is responsible for much of their smell.
